Evacuating, gassing, and sealing containers



Sept. 4, 1956 A. P. BRANT EVACUATING, GASSING AND SEALING CONTAINERS 3 Sheets Sheet 1 Filed June 2, 1955 INVENTOR firi/mr P1574111 WMM-fiA ATTORNEY p 1956 A. P. BRANT EVACUATING, GASSING AND SEALING CONTAINERS 3 Sheets-Sheet 2 Filed June 2, 1955 i M fim w/ a r Sept. 4, 19 56 A. P. BRANT 2,761,604

EVACUA'TLNG, GAS-SING AND SEALING CONTAINERS ATTORNEY United States Patent EVA'CUATlNG, GASSING, AND SEALING CONTAINERS Arthur Paul Brant, Little Valley, N. Y., assignor to The Borden Company, a corporation of New Jersey Application June 2, 1955, SerialNo. 512,684

7 Claims. (Cl. 226-69) This invention relates to a machine for evacuating cans containing food and other air sensitive products, filling the cans so evacuated with an inert gas, and sealing the cans without admission of air.

Evacuation, gassing and sealing of cans is common practice of long standing in many industries.

My invention provides a machine that is relatively inexpensive in proportion to its capacity, is completely automatic, requires no seal against leaks around moving bearing surfaces in the evacuation and gassing steps, keeps the can level in the evacuation and gassing chamber with a minimum of agitation, and delivers them to the final closing step without substantial contamination by air. The invention provides automatically for the predetermined degree of evacuation that is to be used and the pressure to which the inert gas is introduced in the gassing chamber.

Briefly stated, the invention comprises the herein described combination of means for accomplishing the several steps described in dependable, predetermined manner.

The invention will be illustrated by description in connection with the attached drawings to which reference is made.

Fig. 1 is a top plan view of the can evacuating, gassing and sealing apparatus.

Fig. 2 is a side elevation.

Fig. 3 is a fragmentary side elevation on a somewhat enlarged scale. The view is partly in section.

Fig. 4 is a fragmentary side elevation largely in section of the discharge end of the equipment.

Fig. 5 is a diagram showing representative electrical circuits.

The figures are in part diagrammatic.

There are shown can filling and semi-closing equipment with conveyor 12, both of usual type. The conveyor moves the cans near to the elongated evacuating and gassing chamber or tube 14 and adjacent to the charging end 16 thereof. Diverter or sweep ofii plates 18, operated :by the solenoid 20, are provided for directing the cans into any one of the several chambers 14.

Electrical registering device such as counter 22 registers the number of cans which enter the chamber, the cans in passing tripping the arm 23 of the counter.

When the counter .registers the full position of the chamber 14, the counter then starts the motor 24. The motor driven timer (Fig. 5) then activates, in turn, the solenoid 20 for moving the sweep off arm 18 to the position shown at the left in Fig. 1, that is, to the position for not directing any cans from the conveyor 12 into the adjacent chamber 14. The timer then activates the solenoid 26 of plunger arrangement 27 which, through the eccentric door mounting 28, closes the charging door 30. This door has 'a trip element '32 which, in moving downward, depresses the charging plate 34 away from the normal position at the level of the entrance to the chamber and out of position against the spring 36 as shown in Fig. 3.

When this operation is completed, the timer places the chamber 14 in communication with a vacuum pump or other source of reduced pressure (not shown) and causes the resulting evacuation to continue until the pressure falls to a predetermined low level, such as 10 mm. or less of mercury. At this predetermined level, the mercury in manometer 40 closes the circuit between two contact points 41 and 43. Closing this circuit causes the operation to continue. The timer then discontinues the evacuation and this closes the vacuum line through solenoid circuits. The timer now activates the gassing step through diaphragm valve 42 for the inert gas. This introduction of gas is continued until the pressure in manometer 44 reaches the predetermined desired level, ordinarily atmospheric pressure or moderately above. Closing the circuit, as the mercury in 44 reaches the points or terminals 47 and 49 continues the operation until timer 25 activates the next step. The timer then discontinues the introduction of gas and closes the gas inlet line. It will be understood that lines 53 and 55 connect with vacuum and pressure lines 57 and 59, respectively, of Fig. 1.

When the vacuum and gas lines have been closed the timer activates the circuit to the solenoid 45 that raises the rear discharge door 46, so as to open the discharge end of the chamber 14, and then activates the plunger of solenoid mechanism 58 that causes the discharge slide 47 to return to alinement with the discharge end of the conveyor 52. The slide is moved to this can discharge position through the pivotally mounted elbow 56 with spring support 60.

The timer then closes the circuit to motor 48 which drives the chain 50 to the sprocket 51, which, in turn, causes the conveyor 52 to move, in the top reach thereof, in the direction of the discharge end of the chamber 14.

At this stage, the cans slide to the discharge conveyor 62 where they are conducted to the final sealing equipment 64 of standard type.

When the conveyor 52 has discharged all of the cans from the chamber 14, then the timer mechanism acting on the discharge door operating mechanism 45 through microswitch forces downwardly the toggle rod 68 with toggle joint supports 70 for the door 46. When the lower edge of the door strikes the sill 72, the continued downward pressure on the rod 68 acts through the toggle joints 70 to force the door 46 tightly against gasket 74.

Housing 78 encloses the motor 48 and drive equipment operated thereby. These parts are thus sealed from the atmosphere and placed in direct communication with chamber 14. As a result, leaking of air from the outside to the drive mechanism for conveyor 52 and then into the chamber is prevented. Housing 80 encloses the rear door, discharge plate assembly, conveyor 62, and sealing mechanism 64. The space within this housing 80 becomes filled with the inert gas when door 46 is open. This space, on the other hand, is never in communication with the evacuation equipment since the discharge door 46 is opened only during the stage of the cycle when the chamber 14 is .filled with the inert gas.

The materials of construction of the several parts of the machine are those that are usual for like parts in other machines unless specifically stated to the contrary. Thus, the conveyors 12 and 62 are suitably belts of rubber or the like, the door gaskets are the usual type of gasket of natural or synthetic rubber, and the elongated chamber 14 is constructed of welded steel plate shaped suitably to rectangular shape as shown and of sufiicient strength to resist the evacuation. The conveyor 52 extending lengthwise of the said chamber is constructed of parallel spaced chains, of size and spacing to hold upright the cans to be processed.

The operation of the machine is largely evident from the description of it that has been given.

The containers with the product semi-enclosed inside, are taken from the semi-closing machine 10, by a belt conveyor 12, to the entrance of tube 14, the door 30 of 3 which is held in the open position by arm 61 operated by an electrically controlled plunger mechanism 26 acti vated by the timing mechanism 25.

The containers are transferred from belt conveyor 12 into the tube 14 by means of a sweep off arm 18 and a spring loaded hinge track 34, Fig. 1 and Fig. 2.

When a predetermined number of containers have been conveyed from belt 12 onto conveyor chain 52 past counter 22, the counter starts timing switch 25.

The timing switch, being a rotary cylinder, has pegs for tripping one o rmore switches at any desired time during one revolution of the cylinder.

The timing switch, having been activated by the counter, closes the circuit to the solenoid on the sweep oii arm on the next chamber to be filled with containers, allowing the containers on conveyor belt 12 to continue on to the tube being filled.

As the last can enters the tube, the timing switch activates the solenoid on air cylinder 27, thus closing and sealing the door as in Fig. 3.

Also as the last can enters, the circuit from the timing switch stops motor 48, thus stopping conveyor chains 52 inside the chamber.

Vacuum is then applied to the tube through diaphragm valve 38 which is controlled by the timing device of Fig. 5.

Certainty that the operation is stopped unless the pressure is reduced 10 mm. or less in the tube 14 is provided by a manometer 40 which contains mercury. The mercury is drawn to a certain height in the glass tube by the vacuum. At this height the mercury acts as a switch between two contact points in the tube, thus becoming a bypass to keep the timing switch running for a short interval of time. If the vacuum does not draw the mercury to the contacts in the manometer, the circuit is broken and the timing switch stops thus stopping the whole cycle until the defect in the operation is corrected.

The gassing process is controlled in the same manner as the vacuum as shown in another circuit, Fig. 5. Inert gas is applied at approximately 2 pounds gage pressure through valve 42, controlled by a gas switch in the timer 25.

After the gas pressure is applied, the discharge door 46 is opened by air cylinder which is actuated by timing switch circuit.

The timer again starts the motor 48 through the timing switch and the containers are discharged from the tube 14 onto a conveyor belt 62 by means of the sliding rail 47, the solenoid of which is actuated by the microswitch 75.

After the containers have been discharged, the discharge door 46 is again closed and sealed and the entrance door 30 opened. The tube 14 is then filled again for the next cycle.

The opening of the entrance door is the last operation in the timing switch. The rotation of the cylinder in the timing switch stops and does not start until the counter starts the cylinder again.

Parts not shown in detail are conventional. Thus the various solenoid assemblies are conventional in other uses. The counter is suitably a magnetic impulse capacity counter that may be set to close a circuit at any count.

The inert gas used is any one normally used to protect the air sensitive material being canned. Examples are nitrogen, carbon dioxide, and mixtures thereof.

The machine is simple and effective in its operation as well as low in first cost for a given capacity.

The chambers 14 are arranged in parallel. As one chamber is being filled with the cans, another or others are closed and undergoing evacuation and gassing.

When the cans have been sealed in the final closing step at 64, then the closed cans are discharged from this part of the machine by locked valve mechanism that is conventional.

It will be understood that it is intended to cover all changes and modifications of the examples of the invention herein chosen for the purpose of illustration which do not constitute departures from the spirit and scope of the invention.

What is claimed is:

1. In a canning machine including means for delivering unsealed cans to an elongated chamber and for evacuation of air from the chamber and subsequent introduction of inert gas, the improvement comprising a charging door and a discharge door for the said chamber giving, when both doors are closed, substantially air-tight closure, a timing device for making and breaking electrical circuits in sequence, counter mechanism for activating the timing device when the said chamber has been filled with the cans, and means activated by the circuits of said timing device for (1) opening and closing the charging door, (2) opening and closing the discharge door, (3) evacuation of the chamber, and (4) introduction of the inert gas into the chamber, all at predetermined stages of the canning cycle.

2. The machine of claim 1 which includes means sensitive to the extent of evacuation and means sensitive to the pressurt of inert gas subsequently introduced for continuin g the operation of the machine only when evacuation causes the pressure to fall to a predetermined level and when the pressure of the inert gas subsequently introduced within the chamber rises to a predetermined level.

3. The machine of claim 2 which includes a motor driven conveyor extending lengthwise of the said chamber at a level therein to receive and support the cans, means for moving the conveyor with cans thereon in direction to deliver the cans to the discharge end of the chamber, means for opening the discharge door of the chamber after the introduction of the inert gas is completed, means for then starting the said conveyor and continuing its movement to discharge the gassed cans from the chamber, means for closing the discharge door after the discharge of the cans is completed, means for then opening the charging door, and means for introducing into the thus opened charging door and to the said conveyor additional cans to be evacuated and gassed, said timing device, once it is started by the counter mechanism, subsequently activating all the said means in the sequence stated.

4. The machine of claim 1 which includes a conveyor delivering cans adjacent to the entrance of the said chamber, a pivoted sweep otf member for directing the cans from the conveyor into the chamber, the said member being movable to ineffective position and means activated by the timing device for moving the guide member to said inactive position so as to make the directing of cans into the chamber interruptable.

5. The machine of claim 4 which includes a charging plate disposed between the said conveyor and entrance to the chamber, means mounting the plate pivotally at the side thereof adjacent to the conveyor, spring means holding the opposed side of the plate at a level above the bottom of the chamber, and so as to deliver cans from the charging plate into the chamber, and means attached to the charging door for depressing the plate against the spring and below the level of the chamber when the charging door is moved to the closing position.

6. The machine of claim 1 including a conveyor disposed beyond the discharge end of the chamber, a discharge plate bridging the space between the said discharge end and conveyor, and means activated by the discharge door for moving the portion of the said plate adjacent to the chamber away from the chamber when the discharge door moves to the closing position.

7. The machine of claim 1 which includes a conveyor within the said chamber, motor and drive mechanism for the conveyor, and air-tight housing completely enclosing the motor and drive mechanism and placing the space within the housing in free communication with the chamber, so that entrance of air from without to the said housing and then to the chamber is prevented.

No references cited. 

